An object locator for locating a metallic or magnetizable object generates an electromagnetic field by means of a transmitting coil and checks by means of a receiving coil whether the electromagnetic field was changed by the object.
WO 2010/133328 A1 shows a metal detector having two transmitting coils and one receiving coil. The transmitting coils are supplied with phase-shifted alternating currents, and an output signal of a receiving coil which is inductively coupled to the transmitting coils is evaluated. Currents or voltages of the transmitting coils are changed as a function of the received signal in such a way that the received signal is extinguished. The presence of a metallic object in the area of the transmitting and receiving coils may then be inferred from the ratio of the voltages or currents of the transmitting coils.
However, a change in a current flowing through the transmitting or receiving coil of an object locator may also be due to a temperature influence. For example, a current or voltage source for the transmitting coil or a measuring amplifier for the receiving coil may be subject to a temperature drift. Geometric ratios of the coils used may also be changed by a change in temperature.
The drift may be so large that the object can no longer be located with absolute certainty, or is located in a place other than the determined place.
The object of the present disclosure is therefore to provide a method for determining a temperature influence on a sensor for locating metallic or magnetic objects, a corresponding computer program product, and a corresponding sensor. Furthermore, the object of the present disclosure is to provide a measuring device, in particular an object locator, also referred to as a locating device.
The present disclosure achieves these objects by means of the subject matter of the independent claims. Subclaims describe preferred specific embodiments.